The entire disclosure of Japanese Patent Application No.2000-312975 filed on Oct. 13, 2000 including specification, claims, drawings, and summary is incorporated herein by reference in its entirety.
1. Field of the Invention
The present invention relates to a printing press, particularly effective when applied in printing of seals and numbers on stock securities or bank notes.
2. Related Art
An example of outline structure of a conventional printing press for printing seals and numbers on stock securities or bank notes is shown in FIG. 9.
As shown in FIG. 9, a paper feeder 110 has a pile board 111 for stacking up sheets 100 on which patterns have been already printed. The paper feeder 110 also includes a feeder board 112 for feeding the sheets 100 on the pile board 111 to a printing unit 120 one by one. At the leading end of the feeder board 112, a swing device 113 is disposed for transferring the sheets 100 to a transfer cylinder 121a. 
The transfer cylinder 121a is opposing an impression cylinder 122a of the printing unit 120 through transfer cylinders 121b, 121c. A seal cylinder 123 for printing seals is opposing the impression cylinder 122a. A roller group of an ink feeder 124 is opposing the seal cylinder 123. Number printing cylinders 125a, 127a for printing numbers are opposing the impression cylinder 122a. A roller group of an ink feeder 126a is opposing these number printing cylinders 125a, 127a. A transfer cylinder 121d is opposing the impression cylinder 122a. An impression cylinder 122b is opposing the transfer cylinder 121d. Number printing cylinders 125b, 127b for printing numbers are opposing the impression cylinder 122b. A roller group of an ink feeder 126b is opposing these number printing cylinders 125b, 127b. A delivery cylinder 129 is opposing the impression cylinder 122b. 
A sprocket 131 is coaxially disposed on the delivery cylinder 129. A sprocket 132 is provided in a delivery unit 130. A delivery chain 133 is stretched between these sprockets 131 and 132. Delivery grippers 134 are disposed at specified intervals in the delivery chain 133. The delivery unit 130 has piles 135a to 135c for stacking up sheets 100 after printing of seals and numbers.
In such printing press, when the sheets 100, on which patterns are already printed, are transferred onto the transfer cylinder 121 from the pile board 111 of the paper feeder 110 through the feeder board 112, the sheets 100 are transferred to the impression cylinder 122a of the printing unit 120 through the transfer cylinders 121b, 121c, and seals are printed by the seal cylinder 123 and numbers are printed by the number printing cylinders 125a, 127a, and successively they are transferred to the impression cylinder 122b through the transfer cylinder 121d, and numbers are printed by the number printing cylinders 125b, 127b, and they are gripped by the delivery gripper 134 of the delivery unit 130 through the delivery cylinder 129, and conveyed along with running of the delivery chain 133, and discharged onto delivery tables 135a to 135c. 
However, such conventional printing press had the following problems.
(1) Since numbers are printed by the numbering cylinder 125a while printing seals on the sheets 100 by the seal cylinder 123, printing by the seal cylinder 123 may be slightly deviated by light vibration while number printing by the number printing cylinder 125a, thereby resulting in wasted paper.
(2) Since gripping of sheets 100 is changed from the impression cylinders 122a, 122b to the transfer cylinder 121d or delivery cylinder 129 while printing numbers on the sheets 100 by the number printing cylinders 127a, 127b, the terminal end of the sheets 100 may be pulled by the number printing cylinders 127a, 127b by the ink while number printing, and gripping failure of sheets 100 may occur in the transfer cylinder 121d or delivery cylinder 129, and the sheets 100 may be dropped, or the terminal end of the sheets 100 may be pulled to the transfer cylinder 121d side or delivery cylinder 129 side, and number printing failure or waste of paper may occur.
Accordingly, a printing press capable of minimizing such loss of sheets 100 has been keenly demanded.
To solve the problems, the printing press of the present invention comprises an impression cylinder for receiving sheet-like object and holding the sheet-like object, a first printing portion for printing the sheet-like object held by the impression cylinder, a second printing portion disposed at transport direction downstream side of the first printing portion for printing the sheet-like objects held by the impression cylinder, a number printing portion disposed at transport direction downstream side of the second printing portion for number printing the sheet-like object held by the impression cylinder, and a transport cylinder disposed at transport direction downstream side of the number printing portion for receiving the sheet-like object held by the impression cylinder, in which the distance between the outer circumference portion of the impression cylinder opposing the first printing portion and the outer circumference portion of the impression opposing the second printing portion and the distance between the outer circumference portion of the impression cylinder opposing the number printing portion and the outer circumference portion of the impression cylinder opposing the transport cylinder are set more than the length in the circumferential direction of the effective printing area of the sheet-like object, the distance between the outer circumference portion of the impression cylinder opposing the first printing portion and the outer circumference portion of the impression cylinder opposing the number printing portion is set less than the total length of the length of the effective impression are of the impression cylinder and double the length between adjacent effective impression areas of the impression cylinder, and an inspecting unit is further provided for inspecting the sheet-like object supplied to the impression cylinder.
This printing press may further comprise an accumulating unit for receiving and accumulating the sheet-like object from the transport cylinder, and a control unit for controlling the number printing portion to stop number printing on the sheet-like object when the sheet-like object do not satisfy the inspection standard on the basis of a signal from the inspecting unit, and controlling the accumulating unit to accumulate in a position different from the sheet-like object satisfying the inspection standard.
This printing press may further comprise the inspecting unit which inspects one side and other side of the sheet-like object.
This printing press may further comprise the inspecting unit which includes a first inspection cylinder rotatably supported, a first inspection camera for inspecting one side of the sheet-like object held in the first inspection cylinder, a second inspection cylinder rotatably supported, and a second inspection camera for inspecting other side of the sheet-like object held in the second inspection cylinder.
This printing press may further comprise the first inspection cylinder and the second inspection cylinder, which can be suction cylinders.
This printing press may further comprise a first contacting unit for attracting the sheet-like object to the first inspection cylinder side between the feed position for feeding the sheet-like object to the first inspection cylinder and the inspection position of the sheet-like object by the first inspection camera, and
a second contacting unit for attracting the sheet-like object to the second inspection cylinder side between the feed position for feeding the sheet-like object to the second inspection cylinder and the inspection position of the sheet-like object by the second inspection camera.
This printing press may further comprise the first contacting unit and the second contacting unit, which can be brushes.